I have a custom board based on sabresd running android 6.0.1 with 3.X kernel and AR8031 phy. The connection is the same. When I plug cable the two ethernet blinks at same time slowly and takes long to time to identify the network and be able to communicate. After that it works, but only in 10M and networks support 1000M. I double checked all connections and all is correct. Someone experienced this kind of behaviour?